Groundwater-level trends and implications for sustainable water use in the Kabul Basin, Afghanistan

The Kabul Basin, which includes the city of Kabul, Afghanistan, with a population of approximately 4 million, has several Afghan, United States, and international military installations that depend on groundwater resources for a potable water supply. This study examined groundwater levels in the Kabul Basin from 2004 to 2012. Groundwater levels have increased slightly in rural areas of the Kabul Basin as a result of normal precipitation after the drought of the early 2000s. However, groundwater levels have decreased in the city of Kabul due to increasing water use in an area with limited recharge. The rate of groundwater-level decrease in the city is greater for the 2008–2012 period (1.5 meters per year (m/yr) on average) than for the 2004–2008 period (0–0.7 m/yr on average). The analysis, which is corroborated by groundwater-flow modeling and a non-governmental organization decision-support model, identified groundwater-level decreases and associated implications for groundwater sustainability in the city of Kabul. Military installations in the city of Kabul (the Central Kabul subbasin) are likely to face water management challenges resulting from long-term groundwater sustainability concerns, such as the potential drying of shallow water-supply wells. Installations in the northern part of the Kabul Basin may have fewer issues with long-term water sustainability. Groundwater-level monitoring and groundwater-flow simulation can be valuable tools for assessing groundwater management options to improve the sustainability of water resources in the Kabul Basin.     

Assessment of Water Supply as an Ecosystem Service in a Rural-Urban Watershed in Southwestern Mexico City

Studies from the ecosystem services perspective can provide a useful framework because they allow us to fully examine the benefits that humans obtain from socio-ecological systems. Mexico City, the second largest city in the world, has faced severe problems related to water shortages, which have worsened due to increasing population. Demand for space has forced changes in land cover, including covering areas that are essential for groundwater recharge. The city has 880 km² of forest areas that are crucial for the water supply. The Magdalena River Watershed was chosen as a model because it is a well-preserved zone within Mexico City and it provides water for the population. The general aim of this study was to assess the ecosystem service of the water supply in the Magdalena River Watershed by determining its water balance (SWAT model) and the number of beneficiaries of the ecosystem services. The results showed that the watershed provides 18.4 hm³ of water per year. Baseflow was dominant, with a contribution of 85%, while surface runoff only accounted for 15%. The zone provides drinking water to 78,476 inhabitants and could supply 153,203 potential beneficiaries. This work provides an example for understanding how ecosystem processes determine the provision of ecosystem services and benefits to the population in a rural–urban watershed in Mexico City.     

Artificial Groundwater Recharge Zones Mapping Using Remote Sensing and GIS: A Case Study in Indian Punjab

Artificial groundwater recharge plays a vital role in sustainable management of groundwater resources. The present study was carried out to identify the artificial groundwater recharge zones in Bist Doab basin of Indian Punjab using remote sensing and geographical information system (GIS) for augmenting groundwater resources. The study area has been facing severe water scarcity due to intensive agriculture for the past few years. The thematic layers considered in the present study are: geomorphology (2004), geology (2004), land use/land cover (2008), drainage density, slope, soil texture (2000), aquifer transmissivity, and specific yield. Different themes and related features were assigned proper weights based on their relative contribution to groundwater recharge. Normalized weights were computed using the Saaty’s analytic hierarchy process. Thematic layers were integrated in ArcGIS for delineation of artificial groundwater recharge zones. The recharge map thus obtained was divided into four zones (poor, moderate, good, and very good) based on their influence to groundwater recharge. Results indicate that 15, 18, 37, and 30 % of the study area falls under “poor,” “moderate,” “good,” and “very good” groundwater recharge zones, respectively. The highest recharge potential area is located towards western and parts of middle region because of high infiltration rates caused due to the distribution of flood plains, alluvial plain, and agricultural land. The least effective recharge potential is in the eastern and middle parts of the study area due to low infiltration rate. The results of the study can be used to formulate an efficient groundwater management plan for sustainable utilization of limited groundwater resources.     

An Aquifer Storage and Recovery system with reclaimed wastewater to preserve native groundwater resources in El Paso, Texas

The traditional concept of Aquifer Storage and Recovery (ASR) has been emphasized and extensively applied for water resources conservation in arid and semi-arid regions using groundwater systems as introduced in Pyne's book titled Groundwater Recharge and Wells. This paper extends the ASR concept to an integrated level in which either treated or untreated surface water or reclaimed wastewater is stored in a suitable aquifer through a system of spreading basins, infiltration galleries and recharge wells; and part or all of the stored water is recovered through production wells, dual function recharge wells, or by streams receiving increased discharge from the surrounding recharged aquifer as needed. In this paper, the author uses the El Paso Water Utilities (EPWU) ASR system for injection of reclaimed wastewater into the Hueco Bolson aquifer as an example to address challenges and resolutions faced during the design and operation of an ASR system under a new ASR system definition. This new ASR system concept consists of four subsystems: source water, storage space-aquifer, recharge facilities and recovery facilities. Even though facing challenges, this system has successfully recharged approximately 74.7 million cubic meters (19.7 billion gallons) of reclaimed wastewater into the Hueco Bolson aquifer through 10 recharge wells in the last 18 years. This ASR system has served dual purposes: reuse of reclaimed wastewater to preserve native groundwater, and restoration of groundwater by artificial recharge of reclaimed wastewater into the Hueco Bolson aquifer.     

The Role of Climate and Human Influences in the Dry‐Up of the Jinci Springs,China1

Abstract: One of the largest karst springs in North China, the Jinci Springs, dried up and has remained dry since 1994. We develop a correlation analysis with time‐lag and a regression analysis with time‐lag to study the relation between spring flow and precipitation. This allows us to obtain a better understanding of karst hydrological processes by differentiating the contribution of variation in precipitation from anthropogenic impacts on the dry‐up of Jinci Springs. We divided the karstic hydrological processes into two phases: pre‐1961 and post‐1961. In the first phase (i.e., 1954‐1960) the groundwater recharge was affected by precipitation alone, and in the second phase (i.e., 1961‐1994) the groundwater recharge was influenced by both precipitation and human activities. Using precipitation and groundwater recharge data in the first phase, we set up a groundwater recharge model with time‐lags. By running the time‐lags model, we acquired the groundwater recharge likely to occur under the sole effect of precipitation in the second phase. Using a water‐balance calculation, we conclude that the groundwater recharge exhibited statistical stationarity, and the Jinci Springs dry‐up was the result of anthropogenic activities. At least three specific types of anthropogenic activities contributed to the drying‐up of Jinci Springs: (1) groundwater pumping accounts for 51%, (2) the dewatering from coal mining accounts for 33%, (3) and dam‐building 14%. The drying‐up of Jinci Springs meant that the groundwater drained from the aquifer’s fractures, and subsequently changed the structure of the karst aquifer. Although groundwater exploitation has been reduced, the flow at Jinci Springs has not reoccurred.     

Urbanization and its impact on groundwater: a remote sensing and GIS-based assessment approach

The perils of unplanned urbanization and increasing pressure of human activities on hydro-geomorphologic system often result in modification of the existing recharge mechanism, which leads to many environmental consequences. In the present research, an attempt has been made to investigate the applicability of remote sensing and geographical information system (GIS) in dealing with spatial and temporal variability of dynamic phenomena, like urbanization and its impact on groundwater. This paper covers primarily, quantitative and qualitative impacts of urban growth on the behavior of aquifer in Ajmer city (India). Urban growth of the Ajmer city in last 17 years has been estimated from the satellite images. Database related to urbanization and groundwater has been created in GIS. Groundwater recharge has been computed using a water balance approach known as Water Level Fluctuation Methodology. Recharge estimation methodology has been implemented in GIS to introduce the spatial variability of hydro-geological characteristics. Further, temporal and spatial variations in groundwater quality and quantity have been correlated with urban growth using overlay analysis in GIS. The study reveals a general decline in water table and quality with urbanization. Further, remote sensing and GIS technologies have been found useful in assessment of spatial and temporal phenomena of urbanization and its impact on groundwater system.     

Impact of Urban Growth and High Residential Irrigation on Streamflow and Groundwater Levels in a Peri‐Urban Semiarid Catchment

The impact of urbanization on groundwater is not simple to understand, as it depends on a variety of factors such as climate, hydrogeology, water management practices, and infrastructure. In semiarid landscapes, the urbanization processes can involve high water consumptions and irrigation increases, which in turn may contribute to groundwater recharge. We assessed the hydrological impacts of urbanization and irrigation rates in an Andean peri‐urban catchment located in Chile, in a semiarid climate. For this purpose, we built and validated a coupled surface–groundwater model that allows the verification of a strong stream–aquifer interaction in areas with shallow groundwater, higher than some sewers and portions of the stream. Moreover, we also identified a significant local recharge associated with pipe leaks and inefficient urban irrigation. From the evaluation of different future scenarios, we found a sustainable water conservation scenario will decrease the current groundwater levels, while the median flow reduces from 408 to 389 L/s, and the low flow (Q_95%) from 43 to 22L/s. Overall, our results show the relevance of integrating the modeling of surface and subsurface water resources at different spatial and temporal scales, when assessing the effect of urban development and the suitability of urban water practices.     

Hydrogeochemical Indicators of Groundwater Flow Systems in the Yangwu River Alluvial Fan,Xinzhou Basin,Shanxi, China

Based on analysis of groundwater hydrochemical and isotopic indicators, this article aims to identify the groundwater flow systems in the Yangwu River alluvial fan, in the Xinzhou Basin, China. Groundwater δ²H and δ¹⁸O values indicate that the origin of groundwater is mainly from precipitation, with local evaporative influence. d-excess values lower than 10% in most groundwaters suggest a cold climate during recharge in the area. Major ion chemistry, including rCa/rMg and rNa/rCl ratios, show that groundwater salinization is probably dominated by water–rock interaction (e.g., silicate mineral weathering, dissolution of calcite and dolomite and cation exchange) in the Yangwu River alluvial fan, and locally by intensive evapotranspiration in the Hutuo River valley. Cl and Sr concentrations follow an increasing trend in shallow groundwater affected by evaporation, and a decreasing trend in deep groundwater. ⁸⁷Sr/⁸⁶Sr ratios reflect the variety of lithologies encountered during throughflow. The groundwater flow systems (GFS) of the Yangwu River alluvial fan include local and intermediate flow systems. Hydrogeochemical modeling results, simulated using PHREEQC, reveal water–rock interaction processes along different flow paths. This modeling method is more effective for characterizing flow paths in the intermediate system than in the local system. Artificial exploitation on groundwater in the alluvial fan enhances mixing between different groundwater flow systems.     

Environmental Effects of Aquifer Overexploitation: A Case Study in the Highlands of Mexico

There are several environmental processes occurring under aquifer overexploitation conditions. These processes include groundwater table decline, subsidence, attenuation and drying of springs, decrease of river flow, and increased pollution vulnerability, among others processes. Some of these effects have been observed on the Upper Basin of the Lerma River. The Lerma River begins in the SE of the Valley of Toluca at 2,600 m asl, in the wetland known as Lagoons of Almoloya del Río. This wetland is made up of a group of lagoons, which are an important aquatic system from an environmental point of view. The water inflow of this wetland is a discharge of springs, which occur between the fractured volcanic material of the mountain range and granular volcanic–continental deposits of the Valley of Toluca aquifer. The intensive exploitation of the Valley of Toluca aquifer to supply urban and industrial water to Mexico City and Toluca began in 1950 and is responsible for a steady decline of piezometric levels of 1–3.5 m/yr. Other effects of this exploitation—the drying of the wetland, the decrease of river flow and the land subsidence—caused serious ecological and social impacts. The authorities declared this aquifer as overexploited in order to reduce the exploitation and preserve the availability of water resources in this important region.     

丰水型缺水城市地下水资源规划与管理

宁波为典型的丰水型缺水城市,调蓄开发地下水库,是丰水型缺水城市或干旱地区减少地表和地下径流弃水,提高水资源利用率,缓和水资源供需矛盾的重要管理方案.     

GROUNDWATER MANAGEMENT1

There are four groundwater resources to be managed: yield, storage capacity, water-in-storage, and transmissivity. Management concepts have changed over the years, with today's concept which covers comprehensive integrated use of the four groundwater resources with surface water resources to provide the most efficient water service for an area in terms of quantity, quality, and cost. Complete geologic and hydrologic understanding provides a base for formulation of plans which can utilize the techniques of artificial recharge, control of sea water intrusion, and variation of pumping patterns while protecting the resources through proper well construction and abandonment, placement of sanitary landfills, and liquid waste disposal. Plan formulation involves varying recharge and extraction amounts while maintaining the total of pumped groundwater and developed surface water equal to the projected and future demand. Physical limitations of the system must be recognized to assure reality of the plans. Legal constraints should not be placed on the plan formulation process. A present worth or other technique is used to provide an economic comparison among plans. Implementation will entail development of legal and organizational structure, with the most difficult problems relating to the management organization in terms of boundaries and powers.     

Conjunctive Water Use in Confined Basalt Aquifers: An Evaluation Using Geochemistry,a Numerical Model,and Historical Water Level

As withdrawals from deep compartmentalized aquifers increasingly exceed recharge throughout the western United States, conjunctive water use management alternatives have become an applied research priority. This study highlights both details and limitations of the role of irrigation canal seepage as groundwater recharge, revealing the regional limitations of canal seepage as a dependable source of recharge in overdrawn aquifers. A suite of geochemical indicators were used together with a numerical model to evaluate current and future management scenarios focused on recharge derived from seepage from a region‐wide irrigation canal system. Twenty‐five years of static groundwater level data were used to relate spatial trends determined using geochemistry and groundwater modeling with “on‐the‐ground” management practices, which vary based on acreage, crop, and irrigation scheduling. Increasing groundwater age determined using isotope analysis, and declines in potentiometric heads, each correlate with increasing distance from the canal reaches. Predictive modeling indicates that if pumping is gradually reduced, as has been suggested by management agencies, that recharge from canal seepage will be negligible by 2035 due to regional groundwater through‐flow and the pattern of potentiometric head recovery. Unfortunately, historic hydrographs suggest that under current groundwater development conditions most wells are not sustainable, irrespective of proximity to the canal.     

重视地下水资源开发利用与保护

本文着重介绍了国内外地下水开发利用状况，以及造成水质严重污染，影响人类的生存，提出合理开发利用和保护地下水资源，已成为当今世界上的重要课题，提出了和措施，一，强调地下不和地表水是自然界水循环中两个密切相关的环境，必须统一管理，协调开发，二，应用计算机技术，建立管理模型。三，注意解决地表与地下水联合规划，海水入侵，地面沉降，工农业污染，人工回灌等，四，加强对水质和生态环境的保护。     

Spatial Variability of Groundwater Depth and Quality Parameters in the National Capital Territory of Delhi

The groundwater quantity and quality scenario is of much concern in the National Capital Territory of Delhi, India, which necessitates an investigation to envisage the extent of spatial variability of groundwater depth and pollutant concentration levels in this region. Therefore, in this study, an effort was made to generate the spatial variability map of groundwater depth and quality parameters (viz. chloride, electrical conductivity, fluoride, magnesium, and nitrate). Ordinary kriging was used to analyze the spatial variability of groundwater depth and quality parameters, whereas indicator kriging was used to analyze groundwater quality parameters equal to or greater than the pollution threshold values. It was observed that the semivariogram parameters fitted well in the exponential model for water depth and in the spherical model for water quality parameters. The generated spatial variability maps indicated that in 43% of the study area, groundwater depth was within 20 m. The salinity level was higher than 2.5 dS m⁻¹ in 69% of the study area and the nitrate concentration exceeded 45 mg l⁻¹ in 36% of the area. The probability maps showed that about 24% of the area had the highest probability (0.8–1.0) of exceedence of the threshold electrical conductivity value and an area of 2% exhibited the highest probability of exceedence of the threshold value of nitrate concentration in the groundwater. The generated spatial variability and probability maps will assist water resource managers and policymakers in development of guidelines in judicious management of groundwater resources for agricultural and drinking purposes in the study area.     

Estimating Annual Groundwater Evapotranspiration from Phreatophytes in the Great Basin Using Landsat and Flux Tower Measurements

Escalating concerns about water supplies in the Great Basin have prompted numerous water budget studies focused on groundwater recharge and discharge. For many hydrographic areas (HAs) in the Great Basin, most of the recharge is discharged by bare soil evaporation and evapotranspiration (ET) from phreatophyte vegetation. Estimating recharge from precipitation in a given HA is difficult and often has significant uncertainty, therefore it is often quantified by estimating the natural discharge. As such, remote sensing applications for spatially distributing flux tower estimates of ET and groundwater ET (ET_g) across phreatophyte areas are becoming more common. We build on previous studies and develop a transferable empirical relationship with uncertainty bounds between flux tower estimates of ET and a remotely sensed vegetation index, Enhanced Vegetation Index (EVI). Energy balance‐corrected ET measured from 40 flux tower site‐year combinations in the Great Basin was statistically correlated with EVI derived from Landsat imagery (r² = 0.97). Application of the relationship to estimate mean‐annual ET_g from four HAs in western and eastern Nevada is highlighted and results are compared with previous estimates. Uncertainty bounds about the estimated mean ET_g allow investigators to evaluate if independent groundwater discharge estimates are “believable” and will ultimately assist local, state, and federal agencies to evaluate expert witness reports of ET_g, along with providing new first‐order estimates of ET_g.     

RESEARCH INTO THE EFFECTS OF ARTIFICIAL GROUNDWATER RECHARGE,LEA VALLEY,LONDON ENGLAND1

ABSTRACT: Large-scale groundwater abstraction from the Cretaceous Chalk/Lower Tertiary Basal Sands aquifer system of the London Basin in the last 150 years has developed storage of more than 1000 Mm³. Limited operational recharge was undertaken in the 1950's encouraging further detailed study of the wider possibilities. Following a comprehensive hydrogeological reappraisal, an economic and engineering study and pilot-scale experiments, the Lea Valley has been shown to have the greatest potential for recharge. Artificial recharge into the Chalk at a rate of 9000 m³/d appears possible, through acidised 900 mm diameter boreholes. An understanding of the degree of interconnection between the Chalk and Basal Sands and of the causes of changes in quality of recharged water during storage was shown to be of particular importance to the successful operation of any recharge scheme using this system. A two-layer numerical groundwater model of the 800 km² area and a surface/groundwater simulation model have been used to assist with the design of the 84,000 m³/d prototype scheme, and will also help in assessing its efficiency. The models will ultimately be used to manage the operation of the first stage development, now coming into use.     

The “Short Cut” Approach for the Reality of Enhanced Groundwater Contamination

Based on the reality of (a) soil heterogeneity in the vadose zone, (b) enhanced desorption from soil and solubility in water of water insoluble contaminants in the presence of surfactants, and (c) wetting/drying cycles of groundwater recharge (a major cause of fractures formation), a coherent “short-cut” conceptual approach is advanced to account for enhanced groundwater contamination. This is an attempt to close the gap between theory, lab simulations and conventional modelling-based predictions, and observed higher concentrations and more rapid arrival times of contaminants reaching groundwater. Recent data concerning chloride ion and non-ionic surfactants concentrations in aquifers and groundwater wells, combined with previous results concerning the concentrations of tritium, chlorides, metals, organic hydrocarbons and surfactants in the unsaturated and saturated zones of Israel's aquifers, are accounted for in terms of the “short-cut” approach. The contradiction between predictions of groundwater contamination made with conventional, deterministic, homogeneous models and the actual observed behavior of contaminants in soils and aquifers is thus explaind. The “short cut” approach should not be perceived as a better type of model to guide modelling. Rather, it is a proposal for a conceptual change from the realistically invalid, but commonly accepted, conventional “buffer-protective soil/long-term groundwater contamination” to the “short cut” conceptual model to explain the enhanced groundwater contamination actually observed. Although the validity of the proposed approach is strongly supported by the data here presented for the case of Israel (serving as an illustrative case study), selected results and conclusions drawn from studies conducted worldwide suggest its general applicability and usefulness. A major conclusion evolved from the “short-cut” conceptual model is that contemporary groundwater management policies, based on the current perception of groundwater contamination processes and their modelling, may result in an irreversible detrimental effect on the environmental situation in the long run. In any case, prevention, rather than correction/remediation, is strongly recommended as the strategy of choice for rational long-term management of groundwater resources.     

Sources of water pollution and evolution of water quality in the Wuwei basin of Shiyang river, Northwest China

Based on surveys and chemical analyses, we performed a case study of the surface water and groundwater quality in the Wuwei basin, in order to understand the sources of water pollution and the evolution of water quality in Shiyang river. Concentrations of major chemical elements in the surface water were related to the distance downstream from the source of the river, with surface water in the upstream reaches of good quality, but the river from Wuwei city to the Hongya reservoir was seriously polluted, with a synthetic pollution index of 25. Groundwater quality was generally good in the piedmont with dominant bicarbonate and calcium ions, but salinity was high and nitrate pollution occurs in the northern part of the basin. Mineralization of the groundwater has changed rapidly during the past 20 years. There are 23 wastewater outlets that discharge a total of 22.4 x 10(6)m(3)y(-1) into the river from Wuwei city, which, combined with a reduction of inflow water, were found to be the major causes of water pollution. Development of fisheries in the Hongya reservoir since 2000 has also contributed to the pollution. The consumption of water must be decreased until it reaches the sustainable level permitted by the available resources in the whole basin, and discharge of wastes must also be drastically reduced.     

Seeking calm water: Exploring policy options for India's water future

This paper seeks to identify some promising policy options which could be part of a strategic and holistic effort to address India's future water challenges. Significant increases in agricultural water productivity would be a major factor in reducing the need for developing new water sources. Crop diversification, appropriately targeted to account for the present agricultural systems and available water resources, will increase productivity. Furthermore, much more emphasis needs to be placed on effective management of the groundwater resources through renewed efforts to enhance artificial recharge and conservation. Also, efforts should be revived to improve the existing surface irrigation systems. In particular, systems could be reconfigured to provide a more reliable water supply and allow effective community level management, where appropriate. Finally, while some of the increasing demands from domestic and industrial users will be met by the development of groundwater and reallocation of water from the agricultural sector, this will not be sufficient. Given that such conditions are emerging in states with high economic growth and relatively water scarce basins, this will require the further development of water resources. In some cases, these conditions along with the demand for reliable water for high value crops, will be part of the justification for inter‐basin transfers.     

济南市水生态文明与产业布局优化研究

济南市水资源主要存在着地下水限量开采、地表水严重不足、客水利用受到制约等问题。以济南市创建水利部水生态文明城市为背景,研究济南市水生态文明城市建设与产业布局优化,分析了济南市产业布局不合理给水资源保护和利用带来的严峻挑战,提出了以济南市水生态保护为目标的产业优化布局方案,建议大力发展水生态文明城市建设相关产业。